Safety controls are used in a variety of industrial applications. Some safety controls require multiple switches to operate potentially dangerous machines. Mechanical switches, for example, may be used in a safety control system.
Some potentially dangerous machines are switched ON/OFF under the control of optical touch buttons. Optical touch button may detect the presence of an operator's hand, for example, via a beam break sensor, such that when the operator's hand breaks a light beam of the beam break sensor, presence is detected. When operating potentially dangerous machines, a pair of optical touch buttons may be placed apart such that an operator can operate the machinery only when the presence of both hands are detected by the optical touch buttons.